ES2784311T3 - Brake disc - Google Patents

Abstract

A brake disc comprising: -an annular monolithic band (1) having a thickness (S) forming two flat parallel surfaces (2, 3) defining the contact zones with the friction members for the brake and delimited by an outer edge (4) and an inner edge (5); The annular band (1) having the inner edge (5) equipped with a plurality of protuberances or ribs (6); Deriving the annular monolithic band (1) and the plurality of protuberances or ribs (6) from a machining of an unfinished individual mechanical part; - an element (7) for the support of the annular band (1) associated, or that can be associated, with the protuberances or ribs (6) of the internal edge (5) of the annular band (1); The support element (7) being configured to be centrally connected to a hub of a rotating element, characterized in that at least one contact surface (2, 3) of the annular band (1) has a first plurality of grooves ( 9) made at least along the outer edge (4) of the annular band (1); Each first slit (9) being configured to define, in the area involved, a reduction in the thickness (S) of the annular band (1) that comprises at least a section of the external edge (4) of the annular band (1) in the corresponding contact surface (2, 3).

Description

DESCRIPTION

Brake disc

This invention relates to a brake disc.

More specifically, this invention relates to the braking band of disc brakes used on bicycles or motorcycles or, in general, on vehicles of various types with two or more wheels.

The brake discs for these vehicles (for both the front and rear wheels) basically consist of:

- an annular band that forms two flat surfaces on which the friction pads or joints act for the friction transmission of the braking torque (for braking);

- a support for the annular band provided with means to be attached to the internal portion of the annular band or integrated in the annular band and configured to be connected, centrally, to the hub or to an axle of the vehicle wheel.

Several types of brake discs are currently available on the market:

-the one known as monolithic brake disc, with an annular band and support rigidly associated or constructed as a single piece;

-the semi-floating or floating disc, which generally comprises the support and the braking band, but, in addition, is provided with an elastic fastening system, which allows a reduced movement of the braking band with respect to the bracket in the radial direction or in the axial direction or in both directions. The following subcategories of brake discs can be found:

-the round disc, that is, with internal and external profiles with a circular configuration of the braking band;

-the ones known as “wave” or “Daisy” discs, which have a non-circular external or internal profile (or both) of the braking band.

The first of them, the "wave" type of brake disc, is known from patent EP971147.

Said document illustrates a braking band provided with a plurality of deviations or "off-sets" of its inner and outer edges (of identical thickness), which generate an undulating path of the outer braking band. One more category of brake disc is defined as self-ventilating, where the braking band is generally thicker than the types of brake disc mentioned above for the same application, since the ventilation channels or surfaces they must be made inside the braking band. The external braking band of the self-ventilating disc can be of the monolithic type or it can be made of two or more parts associated together to form the band.

In addition to the various structures described above, the brake discs may comprise more structures or greater machining to improve mechanical properties or efficiency during operation.

It should be noted that the quality of a brake disc is evaluated, in particular, by characteristics such as:

-The transmission of braking torque (for braking);

-Resistance to thermo-mechanical stresses;

-The speed of the dispersion of the heat generated by braking.

To maintain or increase this type of function in the brake disc, it is possible to make, for example, holes or grooves (punched or through) on the flat surfaces of the braking band (reducing the mass, draining the water, improving the dispersion of heat and thus improving cooling).

In the case of the brake disc illustrated in patent EP971147, the wavy path of the braking band has the function of reducing the total mass of the disc, improving its cooling and preventing the disc from accumulating debris during use, such as example, mud.

Currently, therefore, the design of the brake discs and, in particular, of the external braking band, focuses on the constant improvement of the aforementioned characteristics, trying to keep production costs low and the possibility of facilitating replacement. quick and easy braking band on vehicles already on the road.

However, the brake disc according to current configurations is not able to fully satisfy all the above-mentioned requirements.

For example, the aforementioned “wave” model cannot always be easily adapted to the original braking system of vehicles already on the road.

Similarly, the self-ventilating brake disc is more complex and expensive to manufacture, requires, in principle, a greater thickness of the braking band and, in this case, cannot replace the non-self-ventilating disc with which the vehicle was equipped in an original way.

Document EP-B2 391 835 describes a brake disc consisting of two half discs of different or equal geometric configurations joined together to form the disc as a whole. Document EP 2 112398 describes a brake disc with a corrugated surface, this type of solution, definitely of the "wave" type, has many disadvantages mentioned above.

Other types of brake discs (round, monolithic with floating or semi-floating coupling) have the possibility of replacing the existing disc in the vehicle, but can present thermo-mechanical limits (particularly in extreme conditions of use) for high-performance vehicles and that require components capable of satisfying safe braking conditions in extreme conditions of use.

The aim of this invention is to provide a brake disc that overcomes the disadvantages of the prior art. More specifically, the aim of this invention is to provide a round type brake disc that can increase the thermo-mechanical performance of the braking band and that is configured to optimize and also improve the performance of the braking system as a whole.

It is another objective of the present invention to provide a round type brake disc that is capable of reducing the costs of manufacturing the braking band, keeping the band dimensions within the parameters so that an assembly with the systems is possible. braking of vehicles already on the road. These objectives are fully achieved with the brake disc according to the present invention, as described in the appended claims.

More specifically, the brake disc comprises an annular monolithic band having a thickness that forms two flat parallel surfaces that define the areas of contact with the friction members for the brake and delimited by an outer edge and an inner edge. The annular band has the inner edge equipped with a plurality of radial protrusions.

The brake disc also comprises an element for supporting the annular band associated with, or which can be associated with, the radial protrusions of the inner edge of the annular band. The support member is configured to be centrally connected to a hub of a rotating member.

In accordance with the invention, the brake disc has at least one annular band contact surface equipped with a first plurality of grooves made at least along the outer edge of the annular band. Also, according to the invention, each first groove is configured to define, in the area involved, a reduction in the thickness of the annular band comprising at least a section of the outer edge of the annular band at the corresponding contact surface.

Thanks to the presence of these grooves (facing or recesses), the braking band has the possibility, for the same mass and inertia as the braking band, to expose a larger exchange surface to the air flow and to increase the capacity heat dissipation.

Preferably, the brake disc has both annular band contact surfaces (inside and outside when mounted on the wheel) with a first and second plurality of grooves made on the outer edge of the annular band itself.

The grooves (facing or recesses) of both contact surfaces considerably increase the exchange surface exposed to the air flow, with a consequent increase in the heat dissipation capacity.

This and other characteristics will become more apparent from the following description of a preferred embodiment of the invention, illustrated by a non-limiting example in the accompanying tables of the drawings, in which:

-Figure 1 illustrates a perspective view of a first side of the brake disc according to this invention;

Figure 2 illustrates a partial perspective view of a second side of the brake disc according to this invention;

-Figure 3 illustrates a front view of the brake disc of Figure 1;

-Figure 4 illustrates a side view of the brake disc of figure 3;

-Figure 5 is a cross section through the line V-V of figure 3;

-Figure 6 illustrates an enlarged detail A of figure 5.

With reference to the accompanying drawings and in particular to Figures 1-3, the brake disc according to this invention, labeled with the number 100 in its entirety, is applicable to vehicles such as bicycles or motorcycles and, for example , three- and four-wheelers, SUVs, go-karts, ultra-light vehicles and vehicles of various types (not illustrated).

The brake disc 100 according to this invention comprises an annular monolithic band 1 having a thickness S which forms two flat surfaces 2 and 3, parallel to each other, which define the areas of contact with friction means (not illustrated) for braking or, in any case, for the transmission of a torque by friction. The two surfaces are bounded by an outer edge 4 and an inner edge 5.

Furthermore, the annular band 1 has the inner edge 5 equipped with a plurality of protrusions 6, in this case radial or, in any case, with a preferably radial direction (ribs).

The brake disc 100 has the annular band 1 and the protrusions 6 formed by a single mechanical part, that is, they are derived from the processing of an unfinished individual mechanical part.

The brake disc 100 also comprises an element 7 for supporting the annular band 1.

The support element 7 is associated with or may be associated with the radial protrusions 6 of the inner edge 5 of the annular band.

Basically, the support element 7 is connected to the braking band 1, according to the two different possibilities.

The first is that the support element 7 can be integrated with the annular band 1 in a single body.

The second is that the support element 7 can be provided with means 8 for connection with the radial protrusions 6 of the inner edge 5 of the annular band 1.

In both cases, the support element 7 is configured to be connected, centrally, to a wheel of the vehicle (bicycle or motorcycle, not illustrated here) or to the hub of a rotating member.

In the illustrated case, the support element 7 (spoke-shaped structure) has the connection means 8 (embodied here as a series of bearings) which are illustrated here by way of example and which do not limit the scope of protection thereof. invention.

According to the invention, at least one of the contact surfaces 2 or 3 of the annular band 1 has a plurality of grooves 9 (facing or recesses) made along the outer edge 4 of the annular band 1.

Each first groove 9 is configured to define, in the area involved, a reduction in the thickness S of the annular band 1 comprising at least one section of the outer edge 4 of the annular band 1 on the corresponding contact surface 2 or 3 ( see also figures 5 and 6).

It should be noted that having grooves, facets, or recesses along at least the outer edge of the annular band allows for a surface discontinuity designed to allow for a greater heat exchange surface area in contact with the air flow.

Preferably, the first plurality of grooves 9 cover the outer circular edge 4 in its entirety of one of the first and second surfaces 2, 3.

More specifically, the grooves 9 are made suitably spaced and preferably equidistant from each other in succession, for the entire circular perimeter of the outer edge 4 of the corresponding surface 2, 3. Preferably, both contact surfaces 2, 3 of the strip annular 1 have a first and a second plurality of grooves 9, 10 made in the outer edge 4 of the annular band 1.

The presence on both contact surfaces of grooves or facing or recesses allows the definition of an aerodynamic architecture that is capable of considerably increasing the heat exchange surface. More specifically, this interaction of airflow aerodynamics interacts not only with the wavy shape created by the recesses of surfaces 2 and 3, but also of the outer and inner edges 4 and 5 of the disc and, consequently, of the entire braking band.

Preferably, the second plurality of grooves 10 cover the entire outer circular edge 4 of the other between the first and second surfaces 2, 3.

In particular, the grooves 10 are made suitably spaced and preferably equidistant from each other in series for the entire circular perimeter of the outer edge 4 of the corresponding surface 2, 3. With this in mind, the first and second plurality of grooves 9, 10 made on the two contact surfaces 2, 3 of the annular band 1 are preferably positioned alternately with each other along the circular perimeter of the annular band 1.

In other words, if a slit 9 or 10 is formed at a point on the outer edge 4 of one of the surfaces 2 or 3, the same area on the opposite surface is continuous and vice versa.

In this way, the geometric structure of the outer edge 4 of the annular band 1 has a series, which is continuous but alternating, of slits 9 or 10 on one side and on the other of the outer edge 4.

The grooves 9 or 10 determine, in the individual mechanical part from which the annular band 1 is formed, a reduction in thickness S in the individual part which is capable of modifying the exchange surfaces of the air flow.

The annular band of an individual mechanical part allows to obtain a high level of mechanical resistance and allows to calculate the optimal thickness reductions S according to precise and optimal parameters for the set of objects.

Each groove 9, 10 made in the surfaces 2, 3 has a curved shape (i.e. a flat, conical and curved portion), preferably a circular arc shape, where the open portion of the arc coincides with the edge section external 4 in contact with ring band 1.

This characteristic allows to arrange the exchange surface for the air flow in a direct and frontal way. In a first embodiment, each groove 9, 10 has the same depth P on the corresponding contact surface 2, 3 of the annular band 1.

Alternatively, the grooves 9, 10 may have different depths P at the corresponding contact surface 2, 3 of the annular band 1.

In other words, several different construction combinations can occur according to the latter concept, that is:

- both the first and the second plurality of slits 9 and 10 have the same depth P; - the first plurality of grooves 9 has a depth P greater than the depth P of the second plurality of grooves 10 or vice versa;

- the individual grooves 9 or 10 of the first and the second plurality can have different depths P even individually from each other.

In other words, the annular band 1 of an individual piece has a thickness S differentiated by the presence of the grooves 9 or 10 along its annular development.

Then, the thickness S of the annular band 1 of an individual piece is given, in the cases where it is present, from the difference between the same thickness S and the depth P of the notches 9 or 10.

It is therefore the case that the one-piece annular band 1 has different, also alternating, thicknesses S along the annular arc to define a single annular piece of diversified thickness S.

This type of choice is a function of the technical design selected and the end use of the brake disc.

Preferably, the brake disc 100 also comprises a third plurality of grooves 11 (facing or recesses) made along the inner edge 5 of the annular band 1.

Each groove 11 of the third plurality being configured to define, in the area involved, a reduction in the thickness S of the annular band 1, comprising at least one section of the internal arched edge 5 of the annular band 1 of the contact surface 2 , 3 corresponding.

According to a first preferred embodiment, the third plurality of grooves 11 is made at least on one of the contact surfaces 2, 3, at least partially on the radial protrusions 6 of the inner edge 4 of the annular band 1.

Also according to a preferred embodiment, the third plurality of grooves 11 is made in at least one of the contact surfaces 2, 3 in an intermediate section of area of the inner edge 5 defined by two consecutive radial protrusions 6.

In another alternative embodiment, the two surfaces may have one of the two configurations of the third plurality of grooves 11 described below. The third plurality of grooves 11 has a curved shape (that is, a flat, conical and curved portion), preferably a circular arc shape, wherein the open portion of the arc coincides with the section of the outer edge 4 in contact with the ring band 1.

It should be noted that the third plurality of grooves 11 has the same depth P on the corresponding contact surface 2, 3 of the annular band 1. Alternatively, the third plurality of grooves 11 may have different depth P on the contact surface 2 , 3 corresponding ring band 1.

A further characteristic of the brake disc 100 is that it comprises a fourth plurality of grooves 12 made in the contact surfaces 2, 3 of the annular band 1 in areas not involved by the first, second and third plurality of grooves 9, 10 and 11.

With this in mind, each groove 12 of the fourth plurality comprises at least a first outer portion 12a defining a partial reduction in thickness S of the corresponding contact surface 2, 3 involved, and a second portion 12b passing from surface 2 up to the surface 3, at least partially processed in the first outer portion 12a.

It should be noted that the fourth plurality of grooves 12 is made in an intermediate zone of the annular band 1 and can have (as shown in Figures 1-3) a range of combinations according to design needs. The fourth plurality of grooves 12 is formed on both contact surfaces 2, 3. The presence of the fourth plurality of grooves 12 has the dual purpose of increasing the thermo-mechanical performance of the annular band 1 and of reducing the mass of the brake disc In its whole.

Preferably, the first portion 12a has an at least semi-curved, preferably semi-circular shape, while the second portion 12b has the shape of a preferably through groove where at least one relative end is made in the inner central part of the first portion 12a.

At least one of these fourth grooves 12 comprises two first portions 12a connected by a second portion 12a, the corresponding grooved ends of which are made at the corresponding inner center of the first two portions 12a.

A brake disc structured in this way achieves the marked objective thanks to the presence of grooves or facing or edge recesses made in the contact surfaces of the annular band.

This structure offers a number of advantages.

The presence of internal and external grooves / facing or recesses, that is, the possibility, for the same mass and inertia of the braking band, to expose a greater exchange surface to the air flow and, potentially, to increase the capacity of heat dissipation compared to existing disc brake solutions (bringing them close, in particular, to the performance guaranteed by the self-ventilating disc brake solution).

Said increased heat dissipation capacity leads to greater smoothness in the behavior and response of the braking system during all its operational phases and this is achieved without increasing the mass of the disc or its moment of inertia with respect to the wheel axis; In other words, it is achieved without penalizing features dynamics of the motorcycle without altering the response of the front suspension, especially in the most intense uses of the motorcycle.

The presence of the indentations in the braking band makes it possible to obtain lower operating temperatures thanks to the greater heat dissipation and this implies a lower thermal stress for the brake pads and increases the resistance of the braking system to “fatigue” ( that is, the ability to keep the braking force intact after repeated operations), thus limiting the overheating of all components of the braking system.

Another advantage induced by the presence of the grooves / facing or recesses is due to the possibility of making one of the recesses / facing or recesses in the visible surface of the braking band, so that they act as an element to indicate the wear of the braking band, for example, making the groove / facing or recess with an adequate depth and being different from the others and, if necessary, with a different color from the others: the signaling of when the wear limit is reached would correspond to the disappearance of the facing or recess.

Another advantage is due to the fact that the presence of grooves or facing or recesses on the surfaces of the braking band provides a greater coating of the friction joint with respect to a similar model of round brake disc.

A further advantage is given by the greater resistance to lateral stresses offered by the structure of the braking band obtained in this way with respect to, for example, the “wave” brake disc models.

Claims (10)

1. A brake disc comprising: - an annular monolithic band (1) having a thickness (S) that forms two flat parallel surfaces (2, 3) that define the contact areas with the friction members for the brake and delimited by an external edge (4) and an inner edge (5); The annular band (1) having the inner edge (5) equipped with a plurality of protrusions or ribs (6); The monolithic annular band (1) and the plurality of protrusions or ribs (6) being derived from a machining of an unfinished individual mechanical part; - an element (7) for the support of the annular band (1) associated, or that can be associated, with the protrusions or ribs (6) of the inner edge (5) of the annular band (1); The support element (7) being configured to be centrally connected to a hub of a rotating element, characterized in that at least one contact surface (2, 3) of the annular band (1) has a first plurality of slits (9) made at least along the outer edge (4) of the annular band (1) ; Each first slit (9) being configured to define, in the area involved, a reduction in the thickness (S) of the annular band (1) comprising at least one section of the outer edge (4) of the annular band (1) in the corresponding contact surface (2, 3). The brake disc according to claim 1, wherein both contact surfaces (2, 3) of the annular band (1) have a first and a second plurality of grooves (9, 10) made on the outer edge (4) of the annular band itself (1). 3. The brake disc according to claim 2, wherein the first and second plurality of grooves (9, 10) made in the two contact surfaces (2, 3) of the annular band (1) are positioned accordingly so that they alternate with each other along the circular perimeter of the annular band itself (1). 4. The brake disc according to any of the preceding claims, wherein each groove (9, 10) has an arcuate shape, where the open portion of the arch coincides with the section of the outer edge (4) involved in the ring band (1). 5. The brake disc according to any of the preceding claims, wherein each groove (9, 10) has an equal depth (P) in the corresponding contact surface (2, 3) of the annular band (1). 6. The brake disc according to any of claims 1-4, wherein the grooves (9, 10) have different depths (P) in the corresponding contact surface (2, 3) of the annular band (1) . The brake disc according to any one of the preceding claims, comprising a third plurality of grooves (11) made along the inner edge (5) of the annular band (1); Each groove (11) of the third plurality being configured in such a way as to define, in the area involved, a reduction in the thickness (S) of the annular band (1) comprising at least one section of the inner arched edge (5) of the band ring (1) on the corresponding contact surface (2, 3). The brake disc according to claim 7, wherein the third plurality of grooves (11) is made, in at least one of the contact surfaces (2, 3), at least partially in the radial protrusions (6 ) of the inner edge (4) of the annular band (1). 9. The brake disc according to any of claims 7 or 8, wherein the third plurality of grooves (11) is made, in at least one of the contact surfaces (2, 3), in a section or a intermediate section of the outer edge (4) defined by two consecutive radial protrusions (6). The brake disc according to any of the preceding claims, comprising a fourth plurality of grooves (12) made in the contact surfaces (2, 3) of the annular band (1) in areas where they are not involved the first, second, and third plurality of slits (9, 10, 11); Each groove (12) of the fourth plurality comprising at least one first outer portion (12a) defining a partial reduction in thickness (S) of the corresponding contact surface (2, 3) involved and a second portion (12b) passing from surface (2) to surface (3), made at least partially in the first outer portion (12a).